Our Dirty Little Secret …An Essay by Bob Wilson

“…We are not figuratively, but literally stardust.”–Neil deGrasse Tyson

Science and religion agree–we are dirt. Dirt and sunlight, and yet we act as if dirt is of little importance. Water is number one, the most exploited resource on the planet, and air if you want to get technical, but in third place is sand. We glue it together with cement or tar, or melt it into glass, and then build our houses, skyscrapers, sidewalks, roadways, bridges, dams, churches and celestial observatories out of it. For our food, we utterly depend on a few inches of topsoil that took millennia to form, and yet we allow it to wash, blow or be bulldozed away as if it were easily replaced.

Human beings progressed from hunting and gathering to farming along rivers like the Nile, the Euphrates and the Mississippi, taking advantage of the mineral wealth of continents washed down from on high by cold rushing water, blended in the turbidity of tributaries, and spread as rich mud across flood plains and deltas. Long before we learned to pan for gold in the headwaters, our first gods were sunlight, water and mud. Our first population booms were made possible by this intermittently replenished fertility, and our first deserts were created by our inability to understand the fragility of the dirt we farmed as we took agriculture farther and farther from the rivers. From the first farmers and city builders of the Fertile Crescent to the green revolution of today, we have treated dirt as an inexhaustible resource, spending it like an endless trust fund. But, is it really so inexhaustible?

Consider sand. It turns out that sand is not as simple as it looked when we played with it in our sandboxes. There are many kinds of sand with different properties, and not every sand can be used for our many specialized applications. Can you imagine anyone importing sand into the sandy desert or spending billions to pour it onto sandy beaches with oceans to wash it away? According to a 2016 BBC report, the United Arab Emirates imported $456 million worth of sand in 2014. Whether that is in pounds or dollars, it is a lot of sand. Desert sand is apparently worthless for building or even for use in the sand traps of the amazingly odd golf courses of Dubai. After hurricanes or “super storms” such as Sandy, U.S. taxpayers pay for millions of tons of sand to replenish beaches that are eaten away from that long row of condominiums along the coast. And the U.S. fracking boom gobbled up 54,000,000 metric tons of high silica sand in 2014. We won’t run out of sand anytime soon, but the cost of many special sand mixes is increasing, as is the global demand.

The use of petroleum-based fertilizers and hydroponic agriculture gives us the illusion that soil quality is no longer a major concern for modern food production. Nothing could be farther from the truth. Fertilizer amends, it does not replace, topsoil; hydroponics provides a tiny share of the world’s food supply. Topsoil is the irreplaceable base of our crop and grazing agriculture. Soil is more than the sum of its parts, x amount of sand, x amount of clay, x amount of water, x amount of organic compost, etc. Soil is more of a living, breathing superorganism. Successful plants depend on an ecosystem of soil microbes and fungi, invertebrates and vertebrates, and passages and canals for the flow of nutrients from subsoil to surface, from mycelium to root hair, from taproot to canopy. If all the topsoil washes or blows away, plants will still grow but not necessarily the plants we want and not necessarily with the nutrients we need. Erosion is not some new threat that we need to convince ourselves of. We have been watching the process for 12,000 years. Civilizations have come and gone with the soil upon which they depended. Most recently, the dust bowl years of the 1930s illustrate what happens when we overplant, overplow, and forget about cover crops. Productive farms are gone with the wind.

Perhaps what is new is our understanding of the process. Soil biology gets better and better, with more tools and a richer understanding of how intricate it all is and how much more there is to learn. What a pity if we allow our traditional practices to destroy the land just as we come to truly know it. Consider one example. Scientists recently found evidence for a subtle but profound feedback loop in forest fertility in the Pacific Northwest. The rivers of the northwest have been moving nutrients from the mountains to the sea for eons. Along with those nutrients, the rivers sent countless salmon into the Pacific Ocean to grow fat on the fertility of the ocean. Those fish then swim back up the river to spawn and be caught by bears that left their partially eaten carcasses in the forest, thus bringing the lost nutrients back to support the great trees with which, along with sand and tar and cement, we build our civilization. The irony is that we have come to understand this marvelous process only after fishing and damming most of the wild salmon runs out of existence and after killing most of the great bears. How many other living cycles must we discover only after stunting or killing them? From dirt we come, and unto dirt we’ll go, so let’s start treating the dirt like an important part of the family.